WASHINGTON - Democratic members of Congress called for details on Homeland Security screening and preparation of immigration enforcement personnel after disclosure Thursday that the ICE agent in a fatal shooting this week in Maine had a record of mental health challenges and aggressive conduct.

The Associated Press noted that David Brouillette, the Immigration and Customs Enforcement agent who shot a Colombian national in Maine, is an Army veteran who has faced serious mental health challenges since early childhood, based on accounts from several close relatives.

The AP contacted congressional leaders and several prominent lawmakers from both parties for comment.

The leading Democrat on the House Homeland Security Committee, Rep. Bennie Thompson of Mississippi, stated that Brouillette's record of aggression and mental health challenges, along with the Maine incident, "directly call into question the supposed screening and preparation ICE performs for its recruits."

"This senseless tragedy must be examined and the agent responsible should be removed from our streets and face justice for his actions," Thompson said in a statement to the AP.

Senate Democratic Leader Chuck Schumer, who led an earlier shutdown of the Department of Homeland Security as Democrats sought limits on immigration enforcement actions, noted that the results of failing to establish safeguards on ICE are now counted in lives lost.

"The Trump administration placed 12,000 agents onto our streets without confirming they were suitable to carry a badge and a gun - and Republicans granted this agency broad authority and no oversight," Schumer said in a statement. "They supported ICE. Now they must work with us to stop additional deaths."

The account of Brouillette's difficult background arrives as the Department of Homeland Security has expanded hiring rapidly, supported by large funding from Republicans in Congress to advance President Donald Trump's deportation plans. It prompts new concerns about the department's process to hire, screen, train and deploy personnel who patrol communities nationwide.

Sen. Susan Collins of Maine, the Republican leader of the Appropriations Committee, referenced her earlier comment that "an impartial investigation into the shooting in Biddeford needs to proceed, as the details surrounding this tragedy are important."

Collins had noted earlier that it is "extremely unfortunate" that the agent lacked a body-worn camera.

The senator secured $20 million for broader use of body-worn cameras and $2 million for deescalation training within the Homeland Security funding measure that Republicans passed to conclude the department shutdown.

"The Democratic government shutdown postponed enactment and implementation of these important safety measures," she said.

At least 10 people have died in encounters with immigration agents since Trump began the enforcement push after returning to office, including 25-year-old Johan Sebastian Duran Guerrero, a Colombian national who was shot and killed by Brouillette on Monday while in his car near his home in the coastal Maine city of Biddeford.

"This report is absolutely appalling - exactly the unacceptable risk that we feared as a result of arrest quotas and inadequate training," said Sen. Richard Blumenthal, D-Conn., in a statement to the AP.

"This agent clearly should never have had a gun - let alone one provided to him by the United States government. And now a man is dead. I will continue demanding answers and accountability," he said.

Sen. Alex Padilla, D-Calif., said Trump and his administration "have encouraged ICE and CBP to enter and disrupt our communities, even if those agents are untrained, improperly screened, or lack experience," referring to Customs and Border Protection.

"The killing of Johan Sebastian Duran Guerrero was horrifying," he said in a statement to the AP, "and there must be a credible, independent, and transparent investigation so that those responsible are held accountable."